Swingable shield assembly for tractor power take-off

ABSTRACT

A swingable tractor PTO shield assembly has an inverted, U-shaped, shield member which is slidably and swingably attached to bracket means on the tractor and which extends above and to the sides of the PTO shaft. The shield member has a plurality of notches on its tractor proximate side edges which slidably engage pins in the bracket to allow the shield member to be swung into and held in a plurality of positions. The shield assembly further includes a cover member swingable on the tractor and slidable on the shield member for covering the space between the tractor and the shield member and which in the lowered position abuts a raised portion on the shield member to prevent movement thereof while both are horizontal.

BACKGROUND OF THE INVENTION

This invention relates generally to shields for tractor power take-offshafts, commonly referred to as PTO shafts, and more particularly toshields that are used over the tractor proximate articulated joint ofthe PTO shaft.

In agricultural and general purpose tractors provided with PTO shafts,the PTO shaft projects a short distance out from the tractor and isexposed to receive a universal joint and a PTO drive shaft for drivingan implement which is mounted on or trailed from the tractor. It iscustomary to provide an inverted, U-shaped shield secured to the tractorand overlying the top and sides of the PTO shaft as shown in the U.S.Pat. No. 2,443,035 granted to L. A. Hardy on June 18, 1948, or toprovide a detachable shield of similar configuration as shown in theU.S. Pat. No. 3,389,763 granted to H. W. Meinert granted on June 25,1968.

Often when using either the permanently mounted or detachable shields,the operator will remove the shield to obtain greater accessibility tothe PTO shaft for attaching or detaching the universal joint. Theoperator will then neglect to remount it due to the time and effortinvolved, thus resulting in a hazardous situation. Further, when theshield is removed from the tractor, it is easy to lose and thus themanufacturer's intent to have a safe vehicle will be circumvented.

In addition, when a universal joint shielding mechanism as shown in theU.S. Pat. No. 3,462,975 granted to A. B. Skromme et al on Aug. 26, 1969,is used the shield must be made as large as possible to accommodate thelargest mechanism size.

SUMMARY OF THE INVENTION

The present invention provides a tractor PTO shaft shield assembly whichis readily swingable to a plurality of positions to provide convenientaccess to the PTO shaft while accommodating a number of differentuniversal joints and universal joint shielding mechanisms with a minimumsize shield assembly. However, with the swinging safety shield, theshield only has to be swung to different positions in order to clear theU-joint shielding mechanism.

The above and additional advantages of the present invention will becomeapparent to those skilled in the art from a consideration of thefollowing detailed description of the preferred embodiment when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one end of a tractor showing the powertake-off area.

FIG. 2 is a side view showing the shield assembly of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, therein is shown the rear of a tractorgenerally designated by the number 10. Protruding from the rear of thetractor 10 is a PTO shaft 12. The exposed end of the PTO shaft 12 isgenerally provided with spines 14 for receiving the yoke of a universaljoint (not shown).

A mounting bracket means 16 which may be a standard part on the tractorsuch as a drawbar support is secured on the rear of the tractor 10. Thebracket means 16 extends to the rear of the tractor on both sides of thePTO shaft 12 and cooperates with a shield assembly generally designatedby the number 20 to protect an operator from the PTO shaft 12.

The shield assembly 20 includes a shield member 22 (shown in a removedposition in FIG. 1) which is supported by the bracket means 16. Theshield member 22 has a top 24 and sides 26 and 28. A raised stop portion30 is formed in the top 24. Parallel slots 32 and 34 are provided in therespective sides 26 and 28. In the tractor proximate edges of the sides26 and 28 are a plurality of paired orientation notches generallydesignated respectively by the numbers 36 and 38.

The shield assembly 20 also includes a cover member 40 which has a cutout 42 in the tractor distal edge. On the tractor proximate edge of thecover member 40 is welded a hinge pin 44 which is pivotally secured in acover bracket 46 which is secured by bolts 48 to the tractor 10.

Referring now to FIG. 2, therein is shown the shield member 22 swingablysecured to the bracket means 16 by a pair of spacers designated by thenumber 48 slidably positioned in the slots 32 and 34 and held by a pairof bolts and washers designated by the number 50.

A pair of holding pins 52 are mounted in the bracket means 16 betweenthe bolts 50 and the rear of the tractor 10. The pins 52 engage thenotches 36 and 38 which are made up of individual notches 36a, 36b, and36c and 38a, 38b, and 38c, respectively, in the shield member 22. Theindividual notches are provided to allow the shield member 22 to be heldin various positions to shield those universal joints with universaljoint shielding mechanisms as disclosed in the Skromme et al patent,ranging in diameter from 7.5 inches up to 11 inches in diameterdesignated by the numbers 54 and 56, respectively, mounted respectivelyon PTO shafts 12a and 12b.

In operation, when the shield member 22 is in position over a minimumdiameter universal joint shielding mechanism 54, the top 24 of theshield member 22 is horizontal. In this position the spacers 48 are inthe tractor proximate portion of the slots 32 and 34 and the pair ofpins 52 engage the notches 36a and 38a. The cover member 40 rests on thetop 24 to cover the space between the tractor 10 and the shield member22 which is required to provide clearance for movement of the shieldmember 22 between its various positions. The cut out 42 straddles theraised stop portion 30 so as to prevent the shield member 22 from beingraised from the horizontal position without first raising the covermember 40 to clear the raised stop portion 30. To prevent the shieldmember 22 from being lowered below its horizontal position, the bottomportions of the notches 36a and 38a are sized so as to be greater thanthe length of the slots 32 and 34.

To move the shield member 22 to its second position, the cover member 40is first lifted and then the shield member 22 is raised until the slots32 and 34 slide longitudinally on the bolts and washers 50, and thenotches 36b and 38b slide into engagement with the pins 52. The shieldmember 32 is moved to its third position in a similar manner untilnotches 36c and 38c are engaged. As the shield member 22 is raised, oncethe cover member 40 clears the raised stop portion 30 the tractor distaledge of the cover member 40 will slide along the top 24 while pivotingabout the hinge pin 44 such that the operator will not have to handlethe cover member 40 after initially lifting it above the raised stopportion 30.

Upon lowering the shield member 22 to its horizontal position, the covermember 40 will automatically drop into place to lock the shield member22 in place.

While the invention has been described in conjunction with a specificembodiment, it is to be understood that many alternatives,modifications, and variations will be apparent to those skilled in theart in light of the aforegoing description. Accordingly, it is intendedto embrace all such alternatives, modifications, and variations whichfall within the spirit and scope of the appended claims.

I claim:
 1. A PTO shield assembly for a tractor having a PTO shaftprotruding therefrom, comprising: an inverted, U-shaped, shield memberextending above and to the sides of the PTO shaft and secured to thetractor for pivotation about a horizontal axis perpendicular to the axisof the PTO shaft; said shield member having orientation means providedtherein for establishing a plurality of .Iadd.operative.Iaddend.pivotable positions for the shield member; and holding means onthe tractor engageable with the orientation means for holding the shieldmember pivoted in .Iadd.any .Iaddend.one of the plurality of pivotablepositions.
 2. The PTO shield assembly as claimed in claim 1 including acover member pivotably secured to the tractor at one end for pivotationabout an axis parallel to the horizontal axis and slidable on the top ofthe shield member at the other end, and wherein the top has a stop meansfor engaging the other end of the cover member when the top ishorizontal and stopping movement of the shield member.
 3. A PTO shieldassembly for a tractor having a PTO shaft protruding therefrom,comprising: an inverted, U-shaped, shield member extending about the topand sides of the PTO shaft; the shield member having mounting means andorientation means provided therein; and bracket means secured at one endon the tractor proximate the PTO shaft and having means at the other endcooperating with the mounting means to define a horizontal axisperpendicular to the axis of the PTO shaft for slidably and swingablymounting the shield member to the bracket means for movementrespectively perpendicular to and around the horizontal axis; thebracket means further including holding means cooperating with theorientation means for positioning and holding the shield member in aplurality of positions around the horizontal axis.
 4. The PTO shieldassembly as claimed in claim 3 wherein the top of the shield member isspaced from the tractor to provide clearance for movement of the shieldmember around the horizontal axis and the tractor proximate portion ofthe top includes a raised stop area; and including a cover membercovering the space between the tractor and the shield member andpivotably secured to the tractor at one end for for pivotation around anaxis parallel to the horizontal axis and slidable on the top at theother end to a lowered position abutting the raised stop area when theshield member is moved towards a raised position from a horizontalposition.
 5. A PTO shield assembly for a tractor having a PTO shaftprotruding therefrom, comprising: an inverted, U-shaped, shield memberextending above and to the sides of the PTO shaft; the shield memberhaving a slot and a plurality of orientation notches provided in oneside respectively parallel to a slot and a plurality of orientationnotches provided in the other side; and bracket means secured at one endto the tractor proximate the PTO shaft and having pivot means at theother end positioned through the slots and forming a horizontal axisperpendicular to the axis of the PTO shaft for slidably and swingablysecuring the shield member to the bracket means for movement radially toand around the horizontal axis; the bracket means including holding pinmeans positioned between the ends of the bracket means having axesparallel to the horizontal axis engageable with the notches in theshield member to hold the shield member in one of a plurality ofpositions established by the plurality of notches when the shield memberis slidably and swingably moved from one of the plurality of positionsto another.
 6. The PTO shield assembly as claimed in claim 5 wherein anotch includes means cooperating with the slot to prevent lowering ofthe tractor distal edge of the top of the shield member below the planeformed when the top is horizontal.
 7. The PTO shield assembly as claimedin claim 5 wherein the top of the shield member is spaced from thetractor to provide clearance for movement of the shield member aroundthe horizontal axis and the tractor proximate portion of the topincludes a raised stop area; and including a cover member covering thespace between the tractor and the top and pivotably secured to thetractor at one end for swinging about an axis parallel to the horizontalaxis and slidable on the top at the other end, the cover member having acut-out at the other end abutting the raised stop area when the tractordistal edge of the top of the shield member is moved above the planeformed when the top is horizontal.
 8. A PTO shield assembly for atractor having a PTO shaft protruding therefrom, comprising: aninverted, U-shaped, shield member spaced from the tractor and extendingabove and to the sides of the PTO shaft; the shield member having a slotprovided in one side parallel to a slot provided in the other side andparallel to the top of the shield member; the shield member furtherhaving a plurality of notches provided in the tractor proximate edge ofthe one side parallel to a plurality of notches provided in the otherside; bracket means secured to one end of the tractor extending to bothsides of the PTO shaft and having pivot means at the other endpositioned through the slots and forming a horizontal axis perpendicularto the axis of the PTO shaft for slidably and swingingly securing theshield member to the bracket means for movement radially to and aroundthe pivot means; the bracket means including pin means positionedbetween the ends thereof having axes parallel to the horizontal axisengageable with the notches in the shield member when the shield memberis slidably and swingably moved from one of the plurality of positionsto another; one of said notches being of greater length than the lengthof the slot to prevent lowering of the tractor distal edge of the top ofthe shield member below the plane formed when the top is horizontal; theshield member including a raised stop area; a cover member covering thespace between the tractor and the top pivotally secured to the tractorat one end for swinging about an axis parallel to the horizontal axisand slidably on the top at the other end, the cover member having a cutout at the other end removably abutting the raised stop area when thetractor distal edge of the top of the shield member is moved above theplane formed by the top when the top is horizontal.